1. Field of the Invention
The present invention relates to a railway car with an overload detector that prevents damage to the railway car and rail tracks caused by overload.
2. Description of the Related Art
Ordinary railway cars support car bodies via air springs on bogies. Japanese Patent Laid-Open Publication No. 5-199604 (Patent document 1) discloses an example of detecting the varied car weight caused by the variation of the number of passengers. The disclosure relates to a loading system for a railway car that converts the air pressure of a plurality of air springs via pneumoelectric converters into electric signals and outputs the same as loading signals. The disclosed pressure sensor detects the inner pressure of all the air springs when applied to a railway car formation in which plural car bodies are connected.
A railway car with a connecting bogie is known in which a connecting bogie is disposed between and connecting two adjacent cars in order to cut down cost of both the railway car and the manufacturing facility. In a railway car adopting such connecting bogies, the restriction of car weight is very severe compared to other railway cars. Thus, when operating the railway car having connecting bogies, a strict load control for each bogie must be carried out so that the load applied on the car body and the track does not exceed the limited range. If the prior art load detector is adopted to detect the car weight varied by the number of passengers, the air pressure of every air spring on the car must be detected. Therefore, the pressure detector must be disposed on every air spring, and a pneumatic piping must be arranged to connect every air spring and the pressure detector. Such arrangement increases not only the cost of the railway car but also the weight of the car body.